1. Field of the Invention
The present invention relates to a data transfer system which includes a portable terminal and navigation equipment.
2. Related Art
JP-A-2000-315296 proposes that personal digital assistance (PDA) receives data on the current position of a vehicle from vehicle navigation equipment and then displays the map data corresponding to the received position data.
However, according to JP-A-2000-315296, the PDA can receive the current position data only when the power switch of the PDA is ON. Therefore a user should turn on the power switch of the PDA, if the power switch is OFF when the current position data is transferred to the PDA.
If the user keeps the power switch of the PDA ON even when he/she drives so that the PDA does not miss receiving the current position data, this leads to waste of power of the PDA.
The present invention has an object to provide a portable terminal capable of automatically switching into a moderate power consumption mode in which the portable terminal can receive position data from vehicle navigation equipment.
The present invention also has an object to provide a portable terminal capable of automatically switching among a plurality of power consumption modes so as not to miss receiving position data from vehicle navigation equipment and so as not to waste the power of the portable terminal.
A portable terminal according to the present invention includes a power switch, connection detector means, position data receiver means, position data storage means and control means. A user operates the power switch for turning on and off the portable terminal. The connection detector means is provided for detecting the connection between the portable terminal and navigation equipment which transfers position data to the portable terminal. The position data receiver means is provided for receiving the position data from the navigation equipment. The position data storage means is provided for storing the position data received by the position data receiver means.
When the connection detection means detects the connection between the portable terminal and the navigation equipment, the control means sets the portable terminal at lowest in a first low-power-consumption mode in which the position data receiver means can receive the position data and the position data storage means can stores the received position data. Then the control means commands the position data receiver means to receive the position data from the navigation equipment, and further commands the position data storage means to store the received position data.
Preferably, the control means sets the portable terminal at lowest in a second low-power-consumption mode in which the connection detector means can detect the connection between the portable terminal and the navigation equipment, even when the power switch of the portable terminal is OFF.